Multi-stage vacuum degasifier



J. F. sEBALD 2,792,904

MULTI-STAGE VACUUM DEGASIFIER May 21, 1957 Filed April 16, 1954 5ShGVebS-Sheei l SEBALD INVENTR JOSEPH F May 21, 1957 J. F. sEBALD2,792Q904 MULTSTAGE VACUUM DEGASIFIER Filed April 16, 1954 3 Sheets-Shee2 INVENTOR May 21, 1957 Filed April 16. 1954 J. F. SEBALD MULTI-STAGEVACUUM DEGASIFIER im ze JOSEPH F. SEBALD INVENTOR.

United States atent U MULTI-STAGE VACUUM DEGASIFIER Joseph F. Sebald,Bloomfield, N. J., assignor to Worthingn ton Corporation, Harrison, N.J., a corporation of Delaware Application April 16, 1954, Serial No.423,560

13 Claims. (Cl. 18S-2.5)

This invention relates generally to water treating apparatus and moreparticularly to an improved multistage vacuum degasiiler that requiresrelatively lighter, and smaller, Vhence less costly, vacuum equipment,and at the same time is designed to meet the limited height and spaceproblems of many installations.

It is well known that raw water contains entrapped anu `dissolvednon-condensible gases such as oxygen, CO2, NH3, which it is advantageousto remove before the water is put to use in connection with a process orinstallation. The removal or release of these entrapped and' dissolvedgases being a function of the pressure in the yequipment which isutilizedfor degasiiication.

One vacuum degasier for this purpose is illustrated in my copendingapplication Serial No. 323,625, which includes means for increasing theeciency of gas removal by providing vapor flow lanes for equalizing thepressure throughout the degasifying tower, allowing the use of lighter,smaller and less costly vacuum equipment to obtain the equivalent orgreater reduction in pressure than previously obtained in similarequipment.

In U. S. Patent No. 2,080,151 to Powell et al., it was shown thatincreased degasitication can be obtained through a two chamberarrangement, operating in series with the vacuum in the secondcompartment greater `than the first.

The present invention covers an improved multi-stage degasitierutilizing two or more compartments having means therebetween acting bothto deliver fluid from one compartment to its adjacent compartment and asa seal between these compartments, and which further utilizes in eachcompartment the vapor ilow lane principles of my above mentionedcopending application, whereby lighter, smaller and less costly vacuumequipment than has heretofore been utilized by vacuum degasiers of thesame capacity, may be used thereon to produce the same or a greaterreduction in pressure in the present apparatus.

Accordingly, it is an Iobject of the present invention to provide avacuum degasifier designed and adapted to meet limited height or spacerequirements which will supply `the required volume of fluid.

It is another object of the present invention to provide a vacuum`degasiiier which will provide an equal or increased amount ofdegasiiication of the Huid passing therethrough with vacuum equipmentwhich is lighter, smaller and less costly.

With these and other objects in View, as may appearl from Vtheaccompanying specification, `the invention consists of various featuresof construction which will be first described in connection with theaccompanying drawings, showing a multistage vacuum degasiiier of apreferred form embodying the invention, and the features forming theinvention will be specifically pointed out in the claims.

In the drawings:

Figure 1 is a side elevation partly in jsection showing the invention.

2,792,904 Patented May 21, 1957 Figure 2 is a cross section taken on theline 2-2 of Fig. l.

Figure 3 is a cross section taken on the line 3-3 of Fig. 1 of theinterior of the second stage compartment.

Figure 4 is a cross section taken thru llne 4-4 of Fig. 3. h

Figure 5 is a cross section taken thru l1ne 5--5 of Fig. 4.

Figure 6 is a side elevation partly in section showing another form ofthe invention.

Figure 7 is a cross section taken on the l1ne 7-7 of Fig. 6. V

Figure 8 is a cross section taken on the line 8-8 of Fig. 6.

Figure 9 is a cross section taken thru line 9-9 of gated tower 2 havinga partition 3 extending across the` approximate horizontal mid-sectionof `the tower and inclined downwardly forming an inlet degasifyingchamber 4 in the upper section and an outlet degasifying chamber 5 inthe lower section. The partition is provided with an opening 6 at itslowest point and from ,this

opening a vertical channel-shaped partition or leg 7,.

connected at its upper most end to the opening and at its open sides tothe inner wall of the tower, forms a downllow passage 8 substantiallyrectangular in cross section and extending downwardly to a pointadjacent the bottom of the tower.

A second channel shaped leg 9 in spaced relation and parallel to to thefirst leg has its Vlower end and side attached at the lower end of theoutlet degasifying chamber 5 and its open side connected to the leg 7 soas to form an upilow passage 10 and a Huid chamber 11 to connect therespective flow passages 8 and 10 to each other whereby a U tube sealgenerally designated 12 is formed, which acts when lled with fluidduring the operation of the degasrilier, as a fluid seal between theinlet and the outlet chamber.

The raw water enters the degasier thru the inlet manifold 13 whichextends diametrically across the upper section of the inlet chamber 4and passes thru a plurality of pipes or conduits 14 extending outwardlyfrom copending application Serial No. 323,625, filed Dec. 2,

1952. The packing assembly is mounted in suitable manner to the walls ofthe tower. ported by the walls of the tower, encloses the spray areaconfining the peripheral annular liquid spray to the top of the packingassembly. The fluid passes by gravity flow downwardly over the `packingarrangement shown in Figs. 2 and 3, in the degasifying space. Incascading over the many tiers of horizontal slats, the flow isrepeatedly broken into tine particles increasing ,the surface area andthereby facilitating the release of the non-condensible gas-es from theliquid during this downward pass.

To further induce the release of the non-.con'densible gases a partialvacuum is maintained in the chamber by a small steam jet ejector 13located at the crown of the tower which is well known in the art andhence not more fully described herein. The ejector is also used toremove the gases as they are `separated from the water by sweeping themotf through the suction caused by the current of steamvpassing thru theejector. This prevents any partial `air `pressure'from `building .up inthe `chamber or the unit would become air-bound.

A baffle 17, also supl afi/sacos The water passes thru the packingassembly le and falls to the inclined partition 3 from there flowingdown thru the opening 6 and entering the downiiow passage 8 of the fluidseal 12. As the level of the water in the U-tube rises above the chamberlll the inlet degasifying chamber is sealed from the outlet degasifyingchamber. The second steam jet ejector' i9 maintains a vacuum in theoutlet chamber which, because of the uid seal is able to beat a greaternegative pressure than the inlet chamber. It is this same diterence ofpressure that forces the fluid to pass from one chamber to another thruthe U-tube seal. The greater pressure in the inlet chamber forces thelevel of the Huid down in the downflow passage 8 causing the level torise in the upflow passage 10, The top of the leg 9 forms a weir 20 overwhich the water fiows into the distributing trays 2l.

The distributing trays 21 are supported by the side walls and serve touniformly distribute the water over the packing' assembly. As the fluidfills the tray it spills over the edges which are provided with serratedrims. Each notch o n the rim is located in such a 'manner that the waterwill fall to one of the slats of the packing assembly. The fluid is thusagain dispersed into small droplets to allow further escape of thenoncondensible gases. The fluid passes downward by gravity iiow thm thepacking and collects in the storage or collection space 23 in the lowerportion of the shell where it is drawn olf thru `a suitable outlet Z4 bymeans of a pump 25.

The ejector 19, maintaining the vacuum in the outlet chamber, draws oitthe gases released in the outlet chamber in the same manner aspreviously stated, receiving its motivating steam through conduit 26from a suitable source not shown. The ejector is mounted in conduit 27'having its inlet Z8 in the upper section of the outlet charnber and itsdischarge end directed into the spray region of the inlet chamber. Thereleased gases are carried by the conduit 27 upward to the spray regionof the inlet charnber and released therein, the non-condensible gasesrising thru the spray are Vented oft" with those gases being releasedfrom the inlet chamber. The steam, when introduced into the cold spray,is condensed and enters the process with the new raw water.

Figure 6 of the drawings shows another form of the invention whichdiffers from the form shown in Figures 1 to.5 of the drawings primarilyin the fact that the modied form of the invention has the inlet andoutlet charnbers adjacent to each other rather than one above the other.VThe modified form is obviously more suitable to installations whereheight limitations are concerned.

The modified form of the invention, includes a shell 29, that is largerin rdiameter but shorter in height than the form shown in Fig. l, withtwo adjacent degasifying chambers 30 and 3l. The inlet chamber 3) isseparated from the outlet chamber 31 by a iirst partition 32 extendingdownward from the top of the shell to a point adjacent the bottom of theshell and a second partition 33 connected to the bottom of the shellextending upward in spaced relation and parallel to the first partitionforming a fluid passage 34 across the diameter of the shell between thepartitions.

It will be understood that while the fluid passage 34 is indicated asequal to the width of the shell that it may be varied as will beunderstood by those skilled in the art as by extending the member 32 tothe bottom of the shell 29 and providing an opening therethroughadjacent the bottom to coact with a channel member attached as indicatedfor the member 9 in the form of the invention illustrated in Figures land 3 of the drawings.

A water inlet manifold 3S extends across the inlet charnber with pipes36 extending transversely from the manifold. The raw water enters thruthe manifold, passes thru the pipes and is sprayed through a pluralityof spray valves 37 over the top of the packing assembly 38. The baiile39 contines the spray to the top area of the packing assembly. The iluidpasses by gravity tlow downward A. over thc packing assembly breakinginto small droplets to release the non-condensible gases and collects atthe bottom 4) of the chamber.

The opening 41 provided at the bottom of the tirst partition permits thewater to pass from the inlet chamber into the upow passage 34 thusforming a tluid seal generally designated 42 between the chambers.

The greater pressure in the inlet chamber tforces the level of the Huidto rise in the passage and flow over the weir 43 into distributing trays44, similar to these previously mentioned, and passes downward thru thepacking assembly 45. The deaerated fluid is stored at the bottom 46 ofthe chamber and is removed by pump 47 as needed thru the outlet 48.

A steam jet ejector 49 is used in the outlet chamber to remove thereleased non-condensible gases and is exhausted into the spray region 50of the inlet chamber where the steam is condensed and the gases arevented ott with those released in the inlet chamber thru a second vejector 51. y

For particular installations where a greater degree 'of purity of thefluid is required, the present invention is mcditied by increasing thenumber of stages. One of more chambers are added between the inlet andoutlet chambers, altering the size of the shell accordingly in height orwidth, depending on space conditions. Each chamber is maintained at alower pressure than the one preceding it by its own ejector, eachejector discharging through conduits into the upper section of thepacking assembly in the preceding chamber where condensation can takeplace. The chambers are separated one from the other by the fluid sealin the same manner as described I for the other forms of the invention.The dimensions of the fluid seals being a function of the dilerence inpressure of adjacent chambers. Thus the partial pressure of the gas inthe outlet chamber will approach zero, necessary to produce maximumdegasification.

It will be understood that the invention is not to be limited to thespecific construction or arrangement of parts shown, but that they maybe widely modiiied within the invention dened by the claims.

What is claimed i-s: 4

l. In a multi-stage vacuum degasiiier, a plurality of degasifyingchambers including an inlet chamber to receive fluid to be degasied andan outlet chamber having an outlet for removing degasied Huid, packingassemblies in each of said chambers forming vapor flow lanes there in,fluid passage means between each of said degasifying chambers including,an upflow leg of predetermined height to form a fluid seal between eachof said chambers whereby chambers on opposite sides of said seal may bemaintained at different sub-atmospheric pressures and at respectivelylower pressures from said inlet stage degasifying chamber to said outletstage degasifying chamber, means for maintaining each of said chambersat their respective predetermined sub-atmospheric pressures, said meansfor maintaining the sub-atmospheric pressures for each of said chambersother than the inlet chamber having their outlets communicating with achamber at higher pressure to deliver freed gases from chamber tochamber and to said inlet chamber, and means on said inlet chamber forpassing said freed gases to atmosphere.

2. ln a multi-stage vacuum degasifier as claimed in claim 1 wherein saidmeans for maintaining said chambers at sub-atmospheric pressures and toremove freed gases therefrom includes vacuum producing means connectedto each of said chambers, said vacuum producing means having its inletconnected to said inlet degasifying chamber exhausting to atmosphere,and said other vacuum producing means having their outlets connected toa chamber at higher pressure.

3. In a multi-stage vacuum degasiiier as claimed in claim l wherein saidmeans for maintaining said chambers at sub-atmospheric pressures and toremove freed gases includes ejectors connected to each of said chambr's,said ejectors for said inlet degasifying chamber eX'- haustirig toatmosphere, and 4each of said other ejectors exhausting into another ofsaid chambers at a higher sub-atmospheric pressure than the chamber towhich they are connected.

4. In a multi-stage vacuum degasifier, an inlet degasifying chamber andan outlet degasifying chamber, packing assemblies in each of saidchambers forming vapor flow lanes therein, means for delivering rawwater to said inlet degasifying chamber, and said outlet degasifyingchamber having an outlet for removing degasified fluid therefrom, fiuidpassage means having a` predetermined height communicating at one `endwith said inlet degasifying chamber and at the otherrend to said outletdegasifying chamber to form a fiuid seal therebetween and to allow saidoutlet degasifying chamber to be maintained at a lower sub-atmosphericpressure than said inlet degasifying chamber, means connected to each ofsaid degasifying chambers for maintaining said chambers at the desiredsub-atmospheric pressure and to remove freed gases from said vacuumdegasifier, said means for main taining the outlet chamber at thedesired sub-atmospheric pressure having it-s outlet communicating withsaid inlet chamber..

5. In a multi-stage vacuum degasifier, partition means transverselydisposed therein to form a first stage degasifying chamber and a secondstage degasifying chamber, means for delivering fluid to be degasifiedto said first stage degasifying chamber, said second stage degasifyingchamber having an outlet for removal of degasified fiuid, packingassemblies in each of said chambers forming vapor fiow lanes therein,fiuid passage means having a predetermined height operatively associatedwith said parttion means and forming a fluid seal between said chambersto allow said second stage degasifying chamber to be maintained at alower sub-atmospheric pressure than said first stage degasifyingchamber, and means connected to the upper end of each of said chambersto maintain the desired sub-atmospheric pressure in its respectivechamber, -said means for maintaining the second stage degasifyingchamber at its desired sub-atmospheric pressure having its outletoperatively connected to said first stage degasifying chamber, and saidfluid passage means to pass fluid from said first stage degasifyingchamber to said second stage degasifying chamber by gravity anddifferential pressure between said chambers.

6. In a multi-stage vacuum degasier as claimed in claim 5 wherein saidmeans for maintaining each of said chambers at the desiredsub-atmospheric pressure includes v-acuum producing means connected tothe upper end of f each of said chambers, said vacuum producing meansconnected to the upper end of said first stage degasifying chamberexhausting to atmosphere, and said vacuum producing means connected tosaid second stage degasifying chamber having an outlet communicatingwith said first stage degasifying chamber.

7. In a multistage vacuum degasilier as claimed in claim 5 wherein saidpartition means is mounted transversely of the longitudinal plane ofsaid vacuum degasifier and at an angle thereto to form a sloping lowerwall for said first stage degasifying chamber, said partition having itslower end in communication with the upper end of said fluid passagemeans and `to pass fluid thereto from said first stage degasifyingchamber by gravity flow.

8. In a multi-stage vacuum degasifying chamber as claimed in claim 5wherein said partition means is mounted substantially parallel to 'thelongitudinal plane of said degasifier and forms a sidewall of said firststage degasifying chamber, and said partition means having an outlet atits lower end to provide continuous communication between said inletdegasifying chamber and said fluid passage means.

9. In a multi-stage vacuum degasifier, a tank, a partition mediallydisposed in said tank transversely of the vertical plane forming acommon wall for a first stage degasifying chamber and a second stagedegasifying chamber, packing means in each of said chambers formingvapor lanes therein, means in the upper end of said first stagedegasifying chamber connected to a source of raw water for deliveringsaid water to the packing means in end connected to said second stagedegasifying chamber` and exhausting into said first stage degasifyingchamber to maintain said second stage degasifying chamber at the`desired sub-atmospheric pressure andV to remove freed gases therefrom, asecond vacuum producing means connected to said first stage degasifyingchamber and exhausting to atmosphere to maintain said first stagedegasifying chamber at sub-atmospheric pressure and to vremove freedgases from said vacuum degasifier, said passage means to pass fluidtherethrough by gravity and under action of the differential pressurebetween said chambers.

10. In a vacuum degasifier as claimed in claim 9 wherein said U-shapedpassage means forming a fluid seal includes a downfiow channel and anupfiow channel in continuous communication at their lower ends, saiddownfiow channel having its upper end connected to said partition and incommunication with said first stage degasifying chamber to receive fiuidtherefrom by gravity, and said upflow channel having its upper end incommunication with said second stage degasifying chamber to deliverfluid thereto under action of the differential pressure between saidchambers.

1l. In a multi-stage vacuum degasifier, a tank, a pair of spacedpartitions medially disposed in said tank substantially to the verticalplane thereof and forming an upfow passage therebetween, said partitionsforming a first stage degasifying chamber and a second stage degasifyingchamber in said tower on opposite sides of said upflow passage, packingmeans in each of said chambers forming vapor flow lanes therein, meansfor supplying water to be degasified to said first stage degasifyingchamber,

said second stage degasifying chamber having an outlet for degasifiedwater, said upfiow passage in continuous communication at its lower endwith said first stage degasifying chamber and to receive fluidtherefrom, said upfiow chamber having an outlet a space height from saidlower end communicating with said second stage degasifying chamber toform a fluid seal between said chambers and to allow said second chamberto be maintained at a lower pressure than said first stage degasifyingchamber, means for maintaining each of said chambers at the desiredsub-atmospheric pressures, said means for maintaining the second stagedegasifying chamber at its desired sub-atmospheric pressure having itsoutlet operatively connected to the first stage degasifying chamber, andsaid upow passage to pass water from said first stage degasifyingchamber to said second stage degasifying chamber by gravity flow andunder action of differential pressure between said chambers.

12. In a multi-stage vacuum degasifier, a tower, a first partitionmedially disposed in said tower substantially parallel to the verticalplane thereof and forming a common wall for a first stage degasifyingchamber and a second stage degasifying chamber, a second partition insaid second stage degasifying chamber spaced from said first partitionto form an upfiow passage therebetween, packing means in each of saidchambers forming vapor fiow lanes, means for supplying iiuid to bedegasified to said first stage degasifying chamber, said second stagedegasifying chamber having an outlet for degasified fluid, said upflowpassage having a predetermined height and having the lower end thereofin continuous communicatin with saidfrst stage degasifying chamber toreceive uid therefrom and its upper end communicating with the upperendy of said second stage degasifying chamber to form a fluid sealbetween said chambers, vacuum producing means connected to each of saidchambers to maintain said second stage degasifying chamber at a lowersub-atmospheric pressure than said rst stage degasifying chamber, saidvacuum means for maintaining the second stage degasifying chamber at thedesired sub-atmospheric pressure having its outlet operatively connectedto said first stage degasifying chamber and said upflow passage to passfluid from said inlet degasifying chamber to said outlet degasifyingchamber by gravity and under action of'diierential pressureV betweensaid chambers.

' 13. In a multi-stage vacuum degasier as claimed in claim 12 whereinsaid vacuum producing means for maintaining each of said chambers at thedesired subatrnospherc pressure includes an ejector-connected to theupper-VA References Cited in the file of this patent UNITED STATESPATENTS 423,606 Haskin Mar. 18, 1890 1,214,656 Dillin Feb. 6, 19172,006,985 Claude et al July 2, 1935v 2,080,151 Powell et al May 11, 19372,235,592 Schneider Mar. 18, 1941 2,605,856 Kirkpatrick et al Aug. 5,1952 2,677,433 Kretzschmar May 4, 1954

